I've used this on my large, short-haired dogs and it's great. Gets right through their coat to the skin, but gently.
This brush worked really well on my rabbit ,it was soft on his skin and great for collecting his moulting coat
I bought the small one as it was the only one in stock at time of purchase. It works amazingly well on short haired dogs! I have two Jack Chi's (Jack Russel Terrier cross with Chihuahua) and it was the perfect size for my smaller dog. For my other medium sized dog, I reckon a medium would've suited better but with the small one I have better control under his neck etc. Easy to clean and I like how all the excess hair stays on the brush for easy removal. Very happy, worth it!